Table 42. Example Size Field Values - ST STM32F4 Series Programming Manual

Core peripherals
Bits 15:8 SRD: Subregion disable bits.
For each bit in this field:
See
Region sizes of 128 bytes and less do not support subregions. When writing the attributes for
such a region, write the SRD field as 0x00.
Bits 7:6 Reserved, forced by hardware to 0.
Bits 5:1 SIZE: Size of the MPU protection region.
The minimum permitted value is 3 (b00010), see
Bit 0 ENABLE: Region enable bit.
SIZE field values
The SIZE field defines the size of the MPU memory region specified by the MPU_RNR
regsiter as follows:
(Region size in bytes) = 2
The smallest permitted region size is 32B, corresponding to a SIZE value of 4.
gives example SIZE values, with the corresponding region size and value of N in the
MPU_RBAR.
SIZE value
b00100 (4)
b01001 (9)
b10011 (19)
b11101 (29)
b11111 (31)
1. In the MPU_RBAR register see
204/260
0: corresponding sub-region is enabled
1: corresponding sub-region is disabled
Subregions on page 197
(SIZE+1)

Table 42. Example SIZE field values

Region size
Section 4.2.8 on page 202
for more information.
SIZE field values
Value of N
32B
1KB
1MB
1GB
4GB
DocID022708 Rev 6
for more information.
(1)
5 Minimum permitted size
10 -
20 -
30 -
b01100 Maximum possible size
PM0214
Table 42
Note